I am a graduate student in nutrition and food studies, and I am currently enrolled in a weight management class. We are questioning the issue of being fit and fat. Is it okay to be fit and fat? What do you feel are the limits? Is it better to be fit and fat than unfit and thin? I am interested in your opinion. Please write back. I love your web site!!

Answer

Dear Reader,

It's hard to say if weight or fitness has a greater impact on overall health, so there's really no clear-cut answer to your question. However, recent research indicates that we should reconsider our beliefs about the relationship between weight and fitness. Weighing a lot or “being fat” is not always a sign of poor health and weighing a smaller amount or “being thin” is not always a mark of physical fitness or good health. And no matter what your size, being physically active on the regular has its benefits.

Many health professionals emphasize the importance of determining a person’s body max index (BMI), which is an estimate of body fat based on your height and weight. BMI is often thought to be a good indicator of the health conditions a person might be at greater risk for. However, the labels of “underweight,” “normal,” and “overweight” can be misleading. For example, some professional athletes are classified at either extreme simply because of how their muscle and fat are distributed. So BMI alone is not necessarily an accurate reflection of a person’s overall fitness.

Clearly, being fit is much more complex than maintaining a particular weight or having a specific BMI. According to the Centers for Disease Control and Prevention (CDC)[2], physical fitness is measured by heart and lung performance, muscular strength and endurance, flexibility, and body composition (ratio of "lean mass" to fat). You’ll notice that weight and BMI are not included. While your weight does not necessarily indicate your fitness level, the CDC emphasizes that being “overweight” may factor into an increased risk for conditions like high blood pressure, heart disease, and diabetes.

It’s important to remember that not all body fat is unhealthy. In fact, different types of fat serve various functions in the body. White fat stores energy and produces hormones that regulate insulin in the body. Brown fat can burn white fat for calories and provide warmth. Studies have shown that lean individuals typically have more brown fat than those who are overweight. Location of fat on the body makes a difference, too. Subcutaneous fat is the type that can be found right under the skin. This differs from visceral fat, which is fat that surrounds your internal organs. When these types of fats are found in excess around the stomach and waist (particularly visceral fat), it can increase the risk for diabetes, heart disease and stroke. If you have excess fat found primarily in the lower parts of the body, like the thighs, you may not have the same type of health risks.

Don’t forget that lifestyle choices are also a sizeable component of overall fitness. For example, someone who does not fall within the "overweight" BMI weight range but is a regular smoker might have less heart and lung capacity than someone who is within the "overweight" BMI weight range. Smoking could also put them at a greater risk for serious conditions like lung disease. By the same token, a person within the "overweight" BMI weight range who gets more physical activity than someone in the "normal" BMI weight range might have a healthier heart and stronger muscles.

No matter how much you weigh, it is recommended that adults get 150 minutes of moderate intensity or 75 minutes of vigorous intensity physical activity, in addition to muscle strengthening activities on two or more days in a week. Need some more information (and maybe a little motivation) to get and stay active? Click on over to the CDC Physical Activity website[3] for tips on activities, videos, and more.